Francisn58 :
neblogai :
There is no K- series i5 3330, so clock multiplyer on your chip is not fully unlocked. You can overclock a bit (100-150MHz) by raising the bus, and ~400MHz more if your motherboard is Z-series model.
Sorry my Cpu is i5 3350P, does this change anything? and my mother board is a gigabyte z77x-UD3H
CPU is still not K-series, so you can not overclock as much as chip is capable of. But your motherboard allows limited overclocking, up to ~3.8Ghz. If you are using stock Intel cooler- It might be worth to get a better one, as stock one is probably not good enough. Nothing expensive is needed, CM Evo 212 would be perfect:
http://www.newegg.com/Product/Product.aspx?Item=N82E16835103099
As for the overclocking itself- you need to enter bios, set CPU ratio multiplier to 'manual' and increase ratio multiplier by +4, for turbo clock of 37x100MHz=3.7GHz. You can also overclock system bus (BCLK) little: it can probably be overclocked to up to 103-105MHz, for 37x103MHz=3.8GHz or so. This is not a high overclock for Ivy Bridge processor, so you most likely do not need to increase voltages for this- stock voltages should be sufficient.